The invention relates to a method for producing an adhesive connection between a workpiece having a metal surface and a workpiece having a plastic surface.
Adhesive connections, particularly welded connections are not easy to produce between workpieces composed of different materials. Welding methods were developed for connecting workpieces composed of metal and of plastic, or workpieces having surfaces composed of metal and of plastic, that produce adhesive connections by exposure to ultrasonic. For this purpose, the plastic surface of the workpiece is provided with an overlay composed of metal, at least at the location or area to which the adhesive connection is to be produced (melt surface). This coating composed of metal is made to soften or melt, using ultrasonic waves, as is the surface composed of metal of the workpiece to be connected. The boundary surfaces composed of metal connect together and remain connected together even after cooling. The basis of such methods is disclosed in DE 40 24 941 and DE 10 2005 005 480. GB 2 121 355 A discloses the application of a lacquer at a metal surface, wherein the lacquer is compatible with the plastic. Ultrasonic welding methods are used in industrial, automated production methods.
The application of metal coatings on plastic surfaces is costly. It requires special production steps, particularly the application of coatings or overlays.